Magnetic Monopoles

Abstract

whether gravitation becomes unified with the other particle interactions at the unification scale.The magnetic charge g of the monopole is typically the "Dirac charge" gD = 1/2e. (Magnetic charge will be defined so that the total magnetic flux emanating from a charge g is 4ng. Electric charge is defined so that the electric flux emanating from a charge e is e.) This magnetic charge is distributed over a core with a radius of order Mi l , the unification distance scale, and the mass of the monopole is comparable to the magnetostatic potential energy of the core.The unification mass scale M x varies from one grand unified model to another. But Mx can be calculated if we make a very strong assumption the "desert hypothesis"-that is, if we assume that no unexpected new inter actions or particles appear between present-day energies (of order 100 GeV) and the unifi cation scale M x. [This assumption is also the basis of the highly successful calculation (6) of the electro weak mixing angle sin 2 Ow.] From the desert hypothesis follows the prediction Mx � 1014 GeV (6); the properties of the monopole may then be summarized by

Magnetic wormholes and topological symmetry

“…Notice that our difficulty in defining a Wilson loop operator in the fundamental representation of SU(2) has been cleverly evaded; any matter that we add to the theory must be in a representation of the underlying SU(3) gauge group, and hence transforms trivially under the center of SU (2). These examples are nicely representative of the general case, which we will now briefly describe [15,25]. Consider the symmetry breaking hierarchy…”

Search for relativistic magnetic monopoles with the ANTARES neutrino telescope

“…Such magnetic monopoles are predicted in any Grand Unified Theory (GUT) in which a larger gauge group breaks down into a semi-simple subgroup containing the explicit U (1) group of electromagnetism. The mass predicted for the monopoles can range from 10 4 GeV to 10 20 GeV depending on the specific model [18].…”

Results of Dark Matter Searches With the Macro Experiment

“…In the framework of Grand Unified Theories (GUT), magnetic monopoles would have been produced in the very early Universe as supermassive (M ∼ 10 17 GeV/c 2 ) topological defects [ 2 ]. One of the primary aims of the MACRO experiment was the search for such particles with a sensitivity well below the Parker bound (i.e.…”

“…upper limits to the monopole flux (see Fig.1). In order to compare the MACRO results to those of other experiments or to theoretical models, we present upper limits for an isotropic flux of bare MMs with magnetic charge equal to one Dirac charge g = g D = e/2α, (where e is the electron charge and α the fine structure constant) and nucleon decay catalysis cross section smaller than 1 mb [ 2 ]. A dedicate analysis for the search for magnetic monopoles accompanied by one or more nucleon decays along their path was also performed, resulting in very strong upper limits …”